Solvent concentration of vitamins



Nov. Q, 1951 s. w. GLOYER 2,573,992

SOLVENT CONCENTRATION OF VITAMINS Filed July 9, 1949 &- /5

rfz 21 INVENTOR. Glam-E Patented Nov. 6, 1951 "UNITED i ISOLYENTCONCENTRATIQN OF vITA nvs Stewart W.: Glo yer. Milwaukee, W ist, assign'or to" Pittsburgh'Plate' Glass Company, a corporation 1." flhnn an a, l

The present invention relatesto a process of i fractionating natural glyceride oils =a-nd it has particular'relation to a' process of frac'tionati-ng glyceride' oils containingsuch vitamins 'as/A.

and D.

vjta rnins H i --A second object 'of the invention is'to provide a process ofthe foregoing type, the application of which does 1 not result-- in' the vitamins in=theoil2= :5 A- third object iSitO'LpIOVi'dB tively inexpensiveto operate: .1

. A fourth object is to provide a.process of ing vitamin concentrates. ofasubstantially better v 2 These and other-Objects of 7the inventionwill' be apparent from consideration, of: thefollowin odor and taste than the original oil.

specification and-the appended claims,

It has heretofore'been proposed to-fra'ctionate a natural glyceride oilconsisting of v,acomplex mixture of saturated andunsaturatedglycerides upon the basis of unsaturation, by use of a selective polar solvent suchasfurfural' or ethyl-aceto' acetate. These solvents are found'to. have a selec tiveaffinity for the more :unsaturated glycerides and by selection of arr appropriate=3temperature of operation it is possible by their application to: the oil to dissolve out the more'unsaturated components as an extract; leaving the saturated components as an undissolved r'afiinate. Th'e unsatu rates are then recoveredby evaporating'oft the solvent; Processes'of this type are; disclosed in Patents Nos. 2,200,390: and-:2,2 00;3Qlvto Stephen:

E. Freeman.

Many natural glyceride" oils .and-lnotably the fish'liver 'oils contain vitaminssuch as A- and D.

These oils are usually objectionableinzodor and taste so that the modern tendency "is to administer them in capsules or pillsr: However, the-concentration of thevitamins inmostflof the oils islow, i

making it necessary .to resort :tocertain premium oils of high vitamin content for capsules or tablets or else compelling the user to take excessive quantities of the capsules in-order to. obtain the' necessaryvitamins; In orderzto'obviate-these objec- "substantialaloss of ajprocess of obtain-;., ing vitamin concentrateswhich is -simple and rela-Y.

appear that-there isrloss ,=ofi :vitamins these;

' "ApplicatiouiJuly 91 1949, Serial Bio. 103,859 1 14c1 ims.'(ci.1g js1)i TES- operations. lFo r these reasons vitamin pillsjof high potency have always remained expensive;

In Tischer Patent No. $12,990,738 it is proposed to treat natural glyceride oils such as cod liver out certain odor or taste constituents without substantially affecting the'vitamin oil.

I oil or the like with furfural in order to dissolve content of the t The present invention is basedupon the-dis covery that natural glyceride oils containing such vitamins as A and D and notably fish liver oils can be treated at moderate expense with selective polar solvents such as furfu'ral or others of the"; type disclosed in Freeman'PatentNo. 2,200,391-

15 to obtain a relatively small extract fraction which is highly enriched in vitamin A arid also vitamin D, if it is present, while leaving a relatively large raffinate fraction which is substantially im- A and D as well as the glyceride oil is extracted away from the polar solvent -'by 'the naphtha,

containingwith naphtha, the major portion of the vitamins leaving a fraction impoverished in vitamins and comprising the major portion of. the free fatty acids and certain taste and odor constituents in' the polar solvent. The removal of the free fatty" acids from the extract solution, therefore, increases the concentration of vitamins in the naphtha extract fraction. The'taste and odor of the naphtha extracted fraction" after the removal of the solvent is considerably better than the original-:oil; Natural, antioxidants such-as? tocopherol and the like are also concentrated in the extract fraction in the primary extraction with polar solvent. Washing this polar solvent extract solutionwith naphtha, that the natural antioxidants concentrate in the naphtha extract or vitamin :concentrate fraction. By application of the invention, it is-thus possible to, obtain vitamin concentrates suitable for, use in capsules and tablets or for other purposes inwhich; a high concentration of vitamins is desirable and-at the same time'obtain fractions of oilof enhanced value, aswell as by-products adaptedfor use as sources and intermediates of pharmaceuticals.

Various of the'solvents disclosed in Freeman- It has beenfound that upon Patent-No. 2,200,391 zwwhichare immiscible with" naphtha'are suitablefor use in the 'practiceof ployed in such ratio and at such temperature as to obtain a relatively small fraction of the total glyceride oil in the extract phase and the major portion in undissolved state in the raidnate phase. In general, the selective polar solvent Will be employed in a ratio of 3 to parts per part of original oil feed as determined by volume. Preferably, the temperature of treat.- ment is so selected that the extract yield is not more than about 30 or and preferably 2 to 30%, of the total glyceride content of the feed oil The amount of naphtha employed in backwashing the polar solvent extract solution generally in a ratio of 3 to 30 parts per part of original oil feed as determined by volume.

The following constitutes a partial list or polar solvents which are immiscible with iso-octane at 25 C. and their use or the use of similar solvents n u c i n th ap ha n o t n thi eei l eni ses 'is W thin e p rv w o th n entio q l A.

Fur-furyl alcohol ylene glycol diformate Glycol dia'cetate' eta h dro sy rep en trile eta .ethex eth l lxcolat E hyl l vu in t riaqe in et oxalat Ethylene glycol Meth l lactate Monoethy eth r f diethylene gly l Methyl levulinate Ethyl acetoacetate EthylrN-methyl carbamate Methyl furoate Methoxy acetaldehyde Cinnamaldehyde Acetonyl acetone Acetamide Betaimethoxy ethyl carbonate Nitrobenzene 'Irimethyl phosphate 2eNitro l-butanol Acetic anhydride Methyl acetoacetate Formic acid ester of the monome'thyl ether 01' ethylene glycol Ethyl maleate Methyl cyanoacetate Furfural Formamide Nitromethane 7 It is to be understood that the use of iso-octane as-the naphtha in the above illustrations is' given merely by way of example and that naphtha as hereinafter used in this specification denotes any hydrocarbon or mixture of hydrocarbons which is immiscible with f-ur-f-ural or other *polar solvent being used and generally is composed of a mixture of parafllnic hydrocarbons such as hexanes, heptanes, octanes, nonanes and decanes.

Suitable ratios of polar solvent to oil and ternperatures of operation for the primary fractionation of a dogfish liver oil into a rafiinate of lower vitamin A potency and extract of higher vitamin A potency with various solvents are given below.

Table B Parts Solvent to Tempera- 5 one Part on ture o Methyl alcohol 10 parts to 1. 39 Methyl lactate 6 parts to 1 57 Moiiomethyl ether of ethylene glycol. 5 parts to 1..-- 40 F ur iuryl alcohol". 4 parts to l 40 Acetic 'ahhydr-idel. 41 Glycol diacetate 5 parts to 1. 51%

I 6 parts to 1 14 6 parts to l. 22 al 8 parts to 1. 17

6 parts to 1. 25% 2 parts to 1. 40 9 parts to 1 60 It is to be understood that the ratios and tem eratur s given, abswe are mer ly y ay 9 exam eh ehe an law e ra es and mpi es than those given above be mployed.- It i to he notes! hat i extraction ma e unde conditions of constant solvent and constant re flux ratio. t e s ze o tract o o 9. dis olve in. the solven in reases a e temperature the so v t ncr a ed whi t e concentration of the vitamins therein is found t e correspondingly lowered. (The method of applying reflux as here referred to is described later the disclosure.) In most instances, itv is preferred, as previously stated, so to operate :as to take an extract fraction constituting. not more than 30 or possibly 40% :of the total feed oil. From 2 to 30% .of the'total feed oil in the ex.- tract fraction is to be preferred.

The polar solvent extract solution produced in the primary Iraoti'onah'on is preferably cooled to about 15 C. to 25 G. and-then contacted either batchw-ise or by methods of countercurrent extraction'with naphtha a ratio of about 3 to parts of naphtha per part =oforiginal oil feed. The naphtha removed the major portion of the glyceride oil, vitamin A'and also vitamin D, if it is present, from the primary extract solution and leaves the free fatty acids, constituents objece tional to taste and odo'nand only minor amounts of the vitamins in the "polar solvent.

A suitable embodiment of apparatus for use in the practice :of the invention is illustrated diagrammatically the single figure of the drawings in which like numerals reter to like parts throughout. In the drawings are shown three columns, 1,11, designed for the countercurrent extraction of the glyceride oils containing the vitamins. JA natur-a'l :glyceride oil containing vitamin A and possibly vitamin D is introduced by line 5 into the column I at about thewmid section thereof. ,A selective polar solvent such as fur-finial .or other of the polar. solvents recognized to have a selective afiini-ty for unsaturated glycerides is introduced into the upper part of column I as indicated at 16. Usually the introduction is efiected at a short distance below the top' :of the column in order to provide :a' quiescent zone in the upper art as indicated at I for. the separation of the rafiinate phase. Raflin'ate oilv containing some dissolved solvent is taken off from the top of the column as indicated "at 18 and may he passed to a suitable some for theremoval of solvent contained therein. The solvent'as removed is drawn oit thmugh :Iine Ml tor storage and re-.

use; After distillation of :the soliient, the rate fi'ria'te impoverished in vitamins A'and' Dpasses off at H to storage or for further treatment as may be desired. 4. I y

In some instances, it may be desirable further to extract the rafimate fraction from column I in order to obtain additional concentration of vitamins therein. For this i purpose, all or a portion of the raflinate phase may be drawn oiI through line 12. Valves I3 and-l4 in :the

lines 8 and I2 constitute means :for regulating and directing the flow of raflinate. Of course,

to promote the flow in these linesappropriate pumps may also be employed, but since they are conventional they have not been illustrated. It is tobe understood that pumpssimilarlymay be employed in anyother portions of the system in order to promote flow .of, and to proportion oils and solvents as maybe required. The rat-.- finate oil containing solvent may be passed to extraction column III to which a solvent such as furfural in a ratio of 3 to 30 parts by volume per part of raflinate feed oil is supplied by, means of a line [6. The raflinate as thus extracted passes out at the top of the column III as indicated at I! to a still l8 for the removal of the,

solvent contained therein. The solvent as re-.

moved is drawn off through line 13 for storage and re-use. The raflinate free of solvent is drawn off through line 2|. Extractsolution taken from the rafilnate obtained in column I is taken off from column III near the bottom thereof as indicated byline 22. This fraction is subjected to distillation instill 24 in order to eliminate solvent whichis passed out throu h line 26 to storage. The extractfrom column III after distillation of the solvent passes off through line 21. It may ass in its entirety to storage or, if preferred, the column III may be so operated as to obtain vitamin concentration in the extract approximately corresponding to the feed oil passing in at to column I. In this latter case,'the extract is passed through line 28 to the feed of column I. "It is also permissible to draw off a portion of'the extract from column III through line 3| and use it as a reflux near the bottom of the column III. The amount of reflux oil used is about .1 to 2 parts by volume to 1 part of rafl'inate feed oil to column III. Suitable valves 32 in' the lines 21, 28 and 3| provide means for the control of the flow of the extract oil. It will be understood that instead of employing a reflux of oil to the lower portion of the column III a reflux of naphtha may be employed or, if preferred, the two may be employed simultaneously. To this end; a line 34 discharges into column III slightly above the bottom thereof and naphtha in a ratio of about .1 to 1 part by volume to 1 part of feed oil to column III may be introduced.

In order to remove free fatty acids as well as objectionable color, odor and taste from the extract as produced 'in column I, it is desirable to refractionate the extract solution in column II by means of a naphtha Wash, whereby the major portion of the glyceride oil, vitamin A and also vitamin D, if present, isextractd from the polar solvent by means of the naphtha, leaving in the polar solvent the free fatty acids as well as constituents of objectionable taste, color and odor. process the polar solvent and naphtha used should be :immiscible in .one another at .the temperatures of operation, or should :become immiscible upon the addition of'small amounts of water, say 1 to of the .polar'solventcon- It .is obvious that in the above.

'to' storage.

6 tent. "Some solvents of this type are disclosed in Table A.

The extract solution from column I is drawn off at the bottom portion of the column through line'36. Various methods of handling this extract solution in order to provide an oil-polar solvent solution feed to column II as well as a reflux medium for columnI are possible. Some of thevariations possible are listed in methods A through E. Method A is the preferred procedure.

Method.A.--All of the extract solution coming from column I may 'pass directly to column II through lines '45 and M. This solution is introduced into column II somewhat below the top of the column in order to provide a quiescent zone 43 in the top portion of column II. If this method is used and it is desirable to use extract product oil as reflux to column I, the reflux oil is supplied through line 66 or through a combination of lines 66 and B3. The details of obtaining this reflux oil or oil-naphtha solution is given later in the disclosure.

MethodB-Under some conditions of operation, especially those using high solvent ratios, it may be desirable to remove some of the polar solvent before the extract solution is sent to column II. In this method all the solution from line 35 is passed to still 31 which preferably is of low pressure, flash type for the removal of about 25 to %of the solvent present in the original extract solution. The solvent is drawn off from still 3'! as indicated, through line 38 and returned'to storage. The concentrated oil solution i drawn ofi from still 3'! through line 39 and is then passed to column II through lines 50 and 4|. In this method as in Method A, reflux oil is supplied through line 66 or a combination of lines 63 and 66.

Method C.If it is desired part of the extract solution from line 3-5 may by-pass still 31 and pass directly to column II, the remainder passing'to still 31 for the removal of about 25 to 90% of the solvent present in this solution. This concentrated solution is then passed to column II through lines 39, 50, and ll. By this combination of methods A and B the amount of oil present in the polar solvent feed to column II can be varied. Relux oil is supplied to column I if it is desired as described in method A and B.

Method D.In method A it may be desirable to obtain extract product reflux oil without treating the whole extract solution with naphtha in column II. In this case, part of the extract solution'is passed to still 3'! for the partial removal of solvent and thence to still 40 for the complete removal of solvent. The solvent from still 40 is drawn off as indicated at 42 and is passed The solvent free extract product oil is then passed to the bottom portion of column I -through line 44.

Method E.-In method B and C it likewise may be desirable to obtain extract product reflux oil without treating the whole extract solution with naphtha in column II. In this case part of the concentrated extract solution passingout of still 31 through line 39 is sent to still 40 for the complete removal of solvent. This solvent free extract product oil is then passed to the bottom portion ofcolumn I through line 44. .LConventional valves 41 control the flow of extract solution, concentrated extract solution and solvent free extract product in lines 45, 36, 39; 44,).and 50. If it is so desired, a reflux of naphtha :v of about. .1; to. 1 part by volume per of original :feed oil may be introduced into.

the bottom zone of column I through line 46;

In .column. II, the extract solution or concentrated extract solution .is'subjected to further extraction by means of a hydrocarbon solvent such as naphtha in a ratio of about to 20 parts per part of original oil (volume basis) introduced through line 59 near the bottom of the column:

and flowing upwardly pountercurrently 'to the extract solution from line 4]. This hydrocarbon effectively dissolves substantially all the glyceride oil and vitamins from the extract solutionfrom column I leaving in the selective polar solvent about 1-3% based upon the original oil of a by-product which passes out through line 52 at or near the bottom. of column II. The by-product solution is subjected to distillation in a still 53 and solvent free by-product is then drawn on through line 56 to storage. The solvent evaporated in the still 53 passes off through line 55 to storage. The hydrocarbon phase carrying in solution nearly all of the glycerides and 'v-ita-- mins A and D extracted from the oil in column I passes out at the top of column II through line 55 and passes through line 57 to still 59 in order to remove the solventwhich is drawn oil through line 5i. Still 55 preferably is of low pressure flash type, operating at as low pressure as is practicable to attain in order to avoid overheating the product. The product from the still 59 includes most of the extracted :glycerides from column I .as well as the vitamins A'and D and passes cutthrough line 62 to storage. If it is desired, a portion of this vitamin concentrate oil may be recycled to column I as reflux through line 55 in order to increase the vitamin concentration of the extracted oil from the latter column. The amount of reflux oil used is about .1 to 2 parts by volume to 1 part of feed oil to column I. Conventional valves 65 in lines 52 and 66 control the amount of oil passing through either of these lines.

An optional method of adding reflux to column I may include the addition through line 63 of a part of the hydrocarbon solution from line 55 as a reflux medium to column I. The amount of solution to be used as reflux is about .1 to part 1 by volume per part of feed oil to column 1. Conventional valves to in lines 57 and B3 control the amount of hydrocarbon solution passing through these lines.

Any of the solvents heretofore described can be employed in the apparatus as shown. However, furfural is particularly satisfactory for the purpose and, as stated, maybe employed in a ratio of about 3 to 30 parts by volume per part of oil being treated. Various vitamin containing oils, notably the fish liver oils, may be employed in the process. These oils include dogs fish liver oil, soup fin shark liver oil, cod liver oil, sardine body oil, gray fish liver oil, viscera oil and the like.

An example illustrating the invention when furfural is used as the selective solvent, dogfish liver oil as vitamin bearing oil and the extraction is carried out in columns Iand II of suitable length is given in Example I.

EXAMPLE I Furfural that has been saturated-with naphtha was pumped to column I through line '6, and dogfish liver oil containing 17,200 units of vitamin A per gram was pumped into column I through line 5. The ratio of solvent feedto oil feed was 20 parts solvent to 1 part feed oil by volume. Extract product oil in a :ratio of 0.21

partto 1 part of feed oil a fed as reflux through line 66 to the bottom portion of the column. The means of obtaining this extract product oil will be later herein described.

Naphtha in a ratio of 041 part to 1 part of feed,

oil was also fed'into the :bottom portion of column I through .line 46. Column I was operated with an F. temperature gradient, the top being maintained at approximately 157 F. andv the bottom at approximately 77 F.

' The rafiinate solution produced in the above fractionation 'was removed from column I through line 8 and passed to still 9 where. all the solvent. was removed. The final rafiinate product oil passed out of the still through line H and was obtained in a yield of 82.2% having a vitamin A potency of 3,440 units per gram. In

this example, the rafiinate was not re-fraction-' ated, however, if it had been desired it could have been pumped through line 12 to column III and refractionated according to the general descriptions previously given.

The extract solution from column I was drawn off through line '38 and all of its was sent to column II through lines 45 and 4|, thereby bypassing still 37. to 1 part of feed oil was pumped into column II through line 49. The naphtha passed countercurrently to the extract solution which entered near the top of the column, and in so doing removed the major portion of the glyceride oil and the vitamin A from the furfural solution. This naphtha solution containing the vitamin concentrate passed from column II through lines 55 and 51 to still 59in which all of the solvent was removed from the oil. A portion of this solvent free extract product oil was fed to the bottom portion of column I as reflux by means of line 66, the remainder of the extract product was sent to storage through line 62. The yield of extract product amounted to' 15.1% of the feed oil and had a vitamin .A potency of 92,800 units per gram.

The major portion of the free fatty acids.

present in the extract solution from column I remain in the furfural when the extract solution is washed with naphtha in column II. Constituents objectionable to odor and taste as well as other minor ingredients, unsaponifiable matter, and lesser amounts of glyceride oil and vita-- mins remain with. the free fatty acids in this Icy-product, iuriural solution.

The. .by-product solution passed from column Column I Solvent ratio, 20:1 based on oil feed rate Solvent :used, naphtha-saturated viurfural Oil reflux, 0.21:1 based :on oil feed rate Naphtha reflux, 0.41::1 based on .oil .feed rate Temperature Top, 157 F.

Bottom 77 F,

Naphtha in a ratio of 14.3 parts Column II All of the extract solution from Column I was fed directly into the top of column II through lines 45 and M.

Naphtha, 14.3:1 based: on on feed rate Temperature, 72 F.-

A number of other examples illustrating the use of column II as a naphtha baokwash'prooess or the use of colunm III as a raiiinate re- III and IV. v v V EXABEPLE II 7 Oil used-Dogfish liver oil containing 10,000 units of vitamin A/gram.

I Column I Solvent ratio, 8:1 basedon oil feed rate Solvent used, anhydrous furfural Oil reflux, none Naphtha reflux, none Temperature, 58-60" F.

I v Unitsof Products rg g z Line Vitamin V V i A/gm' Extract 17. 4 48 24, 800 Raliinatc 82- 6 12 5, 840

The raflinate containing 5,840 units of vitamin A per gram was reiractionated in column IlI under the following conditions:

Column III Solvent ratio, :1 based on roinnatc oil feed rate Solvent used, anhydrous ,furfural Oil reflux, none Naphtha reflux, none Temperature, 96-100 F.

fractionation process are given Examples II,

Unitsoi r o t Products. g Line Extract 40.3 27' iaaco Raifinate v 59.7 21 2, o

EXAMPLE III Oil used.Dogfish liver oil containing 17,300. units vitamin A/gram. e

I Column 1 r Solvent ratio, 8:1 basedon oil feed rate Solvent used, naphtha-saturatedfurfural 7U Naphtha reflux, 0.23:1 based on the oil feed'rate 7 Oil reflux, none 1 I Temperature:

Top, 150 F. Bottom, 68 1",-

Column II All the extract solution from column I was fed directly into the top of column II through lines and 4|.

Naphtha, 5:1 based on the oil feed rate Temperature:

Top, 75 F. Bottom, 68 F.

Units Products 33 Line Vitamin A/gram Extract Y 14.2 62 74,600 Radinatm-.- 84.3 11 1.410 By-Produc l. 5 54 5, 760 Original on.. 17,300

The following example illustrates the concentration of vitamins'in sardine oil (a body oil of low vitamin content):

EXAMPLE IV Oil used-Sardine oil containing 450 units vitamin A/gram and U. S. P. units of vitamin D/gram.

Column I Solvent ratio, 5:1

Solvent used, naphtha-saturated furfural Naphtha reflux, 0.24:1 based on oil feed rate Oil reflux, none Temperature. F.

column II All the extract solution from column I wasted directly into the top of column II through lines 45 and 4|.

Naphtha feed, 5.2:1 based on oil feed rate" Examples V and VI illustrate the use of other polar solvents than furfural in conjunction with the naphtha backwash process for the removal of free fatty acids and other undesirable constituents from extract solutions in which the vitae min A and also vitamin D, if it is present, has

been concentrated.

EXAMPLE V Q' 510 parts of dogflsh liver'oil containing 17,000 units of vitamin A. per gram was thoroughly mixed with 3,250 parts of methyl acetoacetate and the mixture held at 60 C. with intermittent stirring for suflicienttime toensure equilibrium at that temperature. The mixture was finally allowed to separate into two'layers, the upper rallinate layer being impoverished in vitamins and the lower extract layerbeing enriched. ,This lower extract solution layer was. withdrawn and mixed thoroughly with naphthaand the mixture allowed to cool to 27 ,C. The mixture was stirred from time to time until equilibrium hadbeen attained and then the lower methylacetoacetate layer was withdrawn. The solvent was removed by vacuum distillation from both the lower methy -acetoacetate byproductfraction' as'well as the upper naphtha extractfraction; T H

The rafllnate or top fraction obtained 'in the initial separation. with methyl acetoacetat'at' saturated furfural.

11 60 C. was also distilled under vacuum for the removal of the solvent. V v s The products obtained by the above, series of fractionations are given below: 1

Units Vitamin A/gm ' Per Cent Product Yield I .Thenextract fraction had better odor and taste than the original oil.

. EXAMPLE VI 7 525 parts of dogfish liver oil containing 17,000 units of vitaminA per gram. was thoroughly mixed with 2,940 parts vof methyl Cellosolvejand the mixture held at 40 C., with intermittentstiv ring, for suificient time to ensure equilibrium at that temperature; The'mixture was finally allowed to separate into two layers, vthe upper raffinate layer being 'impoverishedin vitamins and the lower extract layer being" enriched; lower extract solution layer was withdrawn'and mixed thoroughly with naphtha and the mixture allowed to cool to 27 C. .'.'I-he mixture was stirred from time ?to =tizneuntil equilibrium had 'beenattainedand then the lowenmethyl Cellosolve layer was withdrawn. The-solvent :Was 'removed by vacuum distillation from both the lower methyl Cellosolve by-product fraction as well as the upper naphtha extract fraction.

The rafiinate or top fraction 'obtained inthe initial separation with methyl Cellosolve at 40 C.

was also distilled under vacuum for the-removal of the solvent.

The products obtained in the above series of fractionations are given below:

Acid. Value Units Vitamin lier Qent Yield m Products 14, 800' as; 500 14 7, 610 s By-Produc 'Ihe extract fraction had better taste and-odor than'the original'oilp- '2 s further-examples, grayfish liver. oil 19,200

*units of vitamin A per grahi was treated with naphtha" saturated furfural the temperatures of separation being 88 F. and -tlieratio being 1-00 parts of grayfishliver oil ,per 600 parts of naph- ,tha, saturated furfural. V

Similarly, soup fin shark liver oil of 25.200 units'of vitamin A per gramfwas treated with naphtha saturated furfural'at 88 R, the ratio being 100 parts ofioilto 400 parts'of naphtha of oil to500 parts by 'weight-of the naphthajsat- "xthisnextractwas found toibe greatly enri hed in This 2 vitamin A contentf vitamiff assays showed that When vitamin D is present.in the original oil, the extract fraction is alsogreatly enriched in this vitamin. g

It is to be understood that in the operation of the apparatus "d'e'escribedit i's preferable to operate the apparatus in such manner asto exclude the oil and solvent from contact with the air. This may be done by blanketing the exposed oilsolvent surfaces with an inert gassuch as carbon dioxide or nitrogen.

Theforms of the invention herein described are to be considered merely as exemplary. Itwill be apparent to vthose skilled in the'art thatnumerous modifications may bemade therein without departure from the spirit of the invention .or; the scope of the appended claims. v

This application is a continuation-in-part of my ,cfippnding application. ,Serial No. 625,767, filed October 31,-1945, now abandoned.

The use of columns for effecting countercurrent extraction of vitaminiferous oils has been described. However; other modesof countercurrentcontact are. contemplated. The process and apparatus as shown inniy'copendingapplication, Serial No. 51,026, filed September 24, 1948, are contemplated ln this process, three centrifuges of the Podbielniak type (see Patent 2,286,157) -are emp1oyedjin place of towers. The furfural extract solution-from, a first centrifuge is passed from the first to a second: where a naphtha reflux is applied. :The naphtha solution is then returned to, the first and the'fu-rfural extract is passed to a third for naphtha backwashing to remove glycerides. With fish liver oil, the vitaminswouldbe taken out in thenaphtha solutionfrom the latter centrifuge.

I claim: 1 W

l. A process ofobtaining glyceride'oil solutions of high vitamin A concentration from fish liver oils containing said vitamin in low concentration, whi p o ss. compr ses; "countercurrently extracting'the gl ceride-oil in; azfirst' vertically elonsated z e w h aal anid polarcompound which is a partial solvent of the oil and is relatively in soluble in naphthagfin'la ratio'of about 3 to 30 A from the solution and leaving the fatty acids solution in the solvent, bypassing the extract solution to a second verticallyelongated'zone and contacting the extract solution in the second zone with naphtha whereby to obtain a solution of glyceride oil and vitamin A in the naphtha and a Icy-product impoverished .in vitamin A and comprising the fatty acids., in solution in the polar solvent and recovering the glyceride oil and vitamin A from thenaphtha.

2. A process as defined in claim 1v in whicha portion of naphtha extract product'oil 'is returned 'as a refiux t' the bottom portion ofthe t j i I. a I. 2 I i 3; A process as reflux of about 0.1 to 1.0 part by 'volume of naphtha and'about 0.1 to 2 parts by volume of extract product oil to 1 part of feedollis -introdefined in claim 1' intwhicha gtvapoe ducedintermediate to the reflux and the solvent feed;

6. A'process of obtaining vitamin concentrates from dogfish liver oil containing vitamins, which process comprises countercurrently extracting the oil in a first vertically elongated zone with furfural, the liquids in the top portion of the zone being maintained at a temperature of about 150 F; and the liquids in the bottom portion being maintained at a temperature of about 68 F., the

i f ur fural being in a ratio of about 3 to 30 parts by volume to -1 part of oil treated and the zone ff'u 'rther being supplied with a reflux to the bottomportion thereof of naphtha extract product oil'of a substantially higher vitamin content per gramthan the original oil, the oil reflux being .in a' ratio of about 0.1 to 2 parts per part of original feed oil by-volume, the extract solution from said zone being further treated with naphtha in ;a second vertically elongated zone in a ratio of to 20 parts to 1 part by volume based upon the original oil feed, the liquids in the top portion of; the secondzone being at a temperature of ,approximately 75" F. and the liquids in the bottomvportion being at a temperature of approximately68 F whereby to obtain a naphtha extract of glyceride oil highly enriched in vitamin content from the second zone, then evaporating the naphtha from the extract.

'7. A process of obtaining vitamin concentrates from dogfish liver oil containing vitamins, which process comprises countercurrently extracting the oil in a first vertically elongated. ,zone with furfural, the liouids in the top portion ofthe zone being maintained at a temperature of about 150 F. and the liquids in the bottom portion being maintained at a temperature of about 68 F.', the

furfural being in a ratio of about 3 to 30 parts by volume to 1 part of oil treated. and the bottom port on of the zone being further supplied with 'a'reflux of naphtha in a ratio of 0.1 to 1.0 part per part of feed oil and a'refiux of solvent free extract oil of a substantially higher vitamin content than the original oil, said extract oil being in a ratio of about 0.1 to 2 parts per 1 part by volume of original feed oil, the extractsolution from the bottom portion of said zone being further countercurrently extracted with naphtha in a second vertically elongated zone in a ratio of about 5 to 20 parts to 1 part by volume based upon the original feed oil, the liquids at the top portion of the second zone being at a temperature of approximately 75 F. and the liquids at the bottom portion being at approximately 68 F. whereby to obtain a naphtha extract of glyceride oil highly enriched in vitamin content from the second zone, then evaporating the naphtha from the extract.

8. A process as defined in claim '7 in which a portion of naphtha extract product is'returned as a reflux to the bottom portion of the first zone, the polar solvent is introduced in the upper portion or the zone and the feed oil is intro- 14 duced intermediate to the reflux and the solvent feed.

9. A process of obtaining glyceride oil solutions of high vitamin A concentration from fish liver "oils containing said vitamin A in low concentration; which process comprises countercurrently extracting the glyceride oil by introducing furfural into an upper portion of a first vertically elongated zone and the'oil into an intermediate portion, the furfural being in a ratio of about 3 to '30 parts per part of oil, introducing a reflux comprising naphtha into the lower part of the zone and maintaining the zone at a temperature to obtain solution in the furfural of about 2 to 30 of the oil as an extract phase comprising unsaturated glycerides, free fatty acids and a concentrate of vitamin A, and further to obtain a reflinate fraction comprising the rest of the oil, extracting out the glycerides and vitamin A from solution in furfural by countercurrently extracting the solution in a second vertically elongated zone with naphtha, whereby to obtain asolution or glyceride, oil and vitamin A in naphtha and ,a by-product impoverished in vitamin A and com-jprising the fatty acids in solution in the furfural, and recovering the glyceride oil and vitamin A from the naphtha.

10. A process of obtaining glyceride oil solutions of high vitamin A concentration from fish liver oils containing said vitamin in low concentration, comprising countercurrently extracting the glyceride oil in afirst vertically elongatedv zone with monoethyl ether of ethylene glycol, in a ratio of about 3 to 30 parts per part of oil, and at a temperature to obtain solution in said monoethyl ether of ethylene glycol of about 2 to 30% of the oil as an extract phase, the extract in the monoethyl ether of ethylene glycol comprising unsaturated glycerides, free fatty acids and vitamin A, and further to obtain a raffinate fraction comprising the rest of the oil, passing the extract solution to a second vertically elongated ether of ethylene glycol and leave the fatty acids in solution therein, whereby to obtain a solution of glyceride oil and vitamin A in the naphtha and a by-product impoverished in vitamin A andcomprising the fatty acids in solution in themonoethyl ether of ethylene glycol, and reccveringthe glyceride oil and vitamin A from the naphtha.

11. A process of obtaining glyceride oil solutions .of high vitamin A concentration from fish liver oils containing said vitamin in low concentration; which process. comprises countercurrently extracting the glyceride oil in a first vertically elongated zone with methyl acetoacetate in a ratio of about 3 to 30 parts per part of oil and at a temperature to obtain solution in said methyl acetoacetate comprising unsaturated glycerides, free fatty acids and vitamin A, and further to obtain a rafiinate fraction comprising the rest of the oil, passing the extract solution to a second vertically elongated zone and contacting the extract solution in the second zone with naphtha to extract out the glycerides and vitamin A from the methyl acetoacetate and leave the fatty acids in solution therein, whereby to obtain a solution of glyceride oil and vitamin A in the naphtha and a by-product impoverished in vitamin A and comprising the fatty acids in solution in the methyl acetoacetate, and re- 15 covering the glycerideoil and vitamin A. from the naphtha.

12. In a process of obtaining glyceride oil products of high concentration of vitamin A, the steps which comprise introducing a feed. of 3 to 30 parts by volume of a polar solvent which is insoluble in naphtha and a partial solvent of fish oil. into an extraction systemat a first point of inlet thereof, introducing a mixture of. .1 to 1 part by volume of naphtha and .1 to 2' parts by volume of fish oil of relatively high vitamin A content at a second point of inlet of the system, flowing the polar solvent and the mixture in countercurrent contact, introducing a continuous feed of 1 part by volume of fish oil of relatively low concentration of. vitamin Av at a third. point of inlet intermediate the first. and second points, drawing off a solution, in naphtha, of raffinate oil containing a lower concentration of. vitamin A than said feed of fish oil, at a. point of outlet near the first mentioned point of inlet and an extract solution of oil enriched in vitamin A in polar solvent at a point of outlet near the second mentioned point of inlet, said system being maintained at such. temperature that 2 to 30% of the original oil is retained in said extract solution, passing the extract solution to a second elongated extraction system and countercurrently contacting the extract solution in the second system with naphtha in a proportion of 3 to 30 parts by volume of naphtha per part of original feed oil to obtain a vitamin A concentrate in the naphtha and a solution of fatty acids in the polar solvent and recovering vitamin A concentrate from the naphtha.

13. In a process of obtaining gl'yceride oil. products of high concentration of vitamin A, the steps which comprise introducing a feed of 3 to 30 parts by volume of polar solvent which is insoluble in naphtha and is a partial solvent of fish oil, in continuous fiow into an extraction system at a first point of inlet thereof, introducing in continuous fiow .1 to 1 part by volume of naphtha at a second'point of inlet of the system, flowing the polar solvent and the naphtha in countercurrent contact, introducing a continuous feed of 1 part by volume of fish oil of relatively low concentration of vitamin A ata point of inlet intermediate of the first and second points, drawing off a solution in naphtha of rafnal oil is retained in said extract solution, passing the extract. solution to. a second elongated extraction system and countercurrently contacting the extract solution in the. second. system with naphtha in a proportion of 3 to 30 parts by volume of naphtha per part of original oil to obtain a vitamin A concentrate. in. naphtha. and a solution of fatty acids in. the polar solvent and recovering said product from the. naphtha.

14.. In a process of. obtaining glyceride oil products of high concentration of vitamin A, the steps which comprise introducing. a feed of 3 to 30v parts by volume of. apolar solvent which, is insoluble in naphtha and is a partial solvent of fishoil in continuous fiow into an extraction system at a first point. ofv inlet, introducing .1 to 2 parts by volume of fish oil of relatively high vitamin A. content at a second. point of inlet i'n the system spaced from. the first mentioned point, causing the polar solvent and the fish oil to permeate 'countercurrently through each other, introducing a continuous feed of 1- part by volume of fish. oil of lower concentration. of vitamin A at. a point of the system intermediate of the first and second points, drawing 01f raflinate comprising oil containing. a lower concentration of vitamin A than said feed of fish oil at a. point of outlet near the. first mentioned point. and an extract solution in polar solvent of oil of higher concentration of vitamin A than said feed of fish oil at a point of outlet near the second mentioned point, said system being maintained at such temperature that 2 to 30% of the original oil is retained in said extract solution, passing the extract solution to a second extraction system and countercurrently contacting the extract solution in the second system with naphtha in a proportion of 3' to 30 parts by volume of naphtha per part of original feed oil' to obtain. a vitamin A concentrate in naphtha and a solution; of fatty acids in the polar solvent and recovering said product from the naphtha.

STEWART W. GLOYER.

REFERENCES CITED The following references. are of record in the file of this patent:

' UNITED STATES PATENTS Number Name Date 2,200,390 Freeman May 14,- 1940 2,347,460 Buxton Apr. 25, 1944 2,355,605 Ruthrufi et a1. Aug. 15', 19% 2,380,418 Dombrow July 31, 1945 2,394,968 Van Orden Feb. 12,. 1946 OTHER REFERENCES Ser. No. 379,550, Grandel (A. 12. 0.), published May 11,1943. 

1. A PROCESS OF OBTAINING GLYCERIDE OIL SOLUTIONS OF HIGH VITAMIN A CONCENTRATION FROM FISH LIVER OILS CONTAINING SAID VITAMIN IN LOW CONCENTRATION, WHICH PROCESS COMPRISES COUNTERCURRENTLY EXTRACTING THE GLYCERIDE OIL IN A FIRST VERTICALLY ELONGATED ZONE WITH A LIQUID POLAR COMPOUND WHICH IS A PARTIAL SOLVENT OF THE OIL AND IS RELATIVELY INSOLUBLE IN NAPHTHA, IN A RATIO OF ABOUT 3 TO 30 PARTS OF THE SOLVENT PER PART OF OIL, INTRODUCING A REFLUX COMPRISING A SMALL AMOUNT OF NAPHTHA INTO THE ZONE NEAR THE BOTTOM THEREOF AND THE ZONE BEING MAINTAINED AT A TEMPERATURE TO OBTAIN SOLUTION IN SAID SOLVENT OF ABOUT 3 TO 30 PERCENT OF THE OIL AS AN EXTRACT PHASE, THE EXTRACT IN SAID SOLVENT COMPRISING UNSATURATED GLYCERIDES, FREE FATTY ACIDS AND VITAMIN A, AND FURTHER TO OBTAIN A RAFFINATE FRACTION COMPRISING THE REST OF THE OIL, EXTRACTING OUT THE GLYCERIDES AND VITAMIN A FROM THE SOLUTION AND LEAVING THE FATTY ACIDS IN SOLUTION IN THE SOLVENT, BY PASSING THE EXTRACT SOLUTION TO A SECOND VERTICALY ELONGATED ZONE AND CONTACTING THE EXTRACT SOLUTION IN THE SECOND ZONE WITH NAPHTHA WHEREBY TO OBTAIN A SOLUTION OF GLYCERIDE OIL AND VITAMIN A IN THE NAPHTHA AND A BY-PRODUCT IMPOVERISHED IN VITAMIN A AND COMPRISING THE FATTY ACIDS IN SOLUTION IN THE POLAR SOLVENT AND RECOVERING THE GLYCERIDE OIL AND VITAMIN A FROM THE NAPHTHA. 